I had too many heirloom tomatoes, and didn't want them to go to waste, so I decided to roast them and make a vegetable sauce. Most recipes called for using tomato paste as a thickener, and I didn't have any on hand, plus I don't like using it because it can turn tomato-based sauces bitter. So I decided to try and use my lonely sweet potato sitting on my kitchen and staring at me, as the thickener. So this turned more into a thick vegetable sauce. I know from baking science that potatoes are mainly starch and are used in bread baking for moisture, to thicken soups and pie fillings, and I have used dehydrated potato flakes as a gluten-free gravy thickener.
So a light bulb went off in my head, and I thought to roast the sweet potato along with my tomatoes and see if it would work as a thickener in my sauce. Besides I liked the idea of using a sweet potato because often times roasted heirloom tomatoes can get bitter, and sometimes it's necessary to add a sugar to sauce. So a sweet potato would naturally sweeten the sauce, too.
In the end, the roasted sweet potato worked like a charm - it added some nice subtle sweet notes to the sauce and thickened it with a nice silky texture! The all natural sauce did not separate into tomatoes and water, either. The sweet potato also added a natural orange tinge to the sauce, which was kind of fun and new and different!We want to help prevent food waste and show you ways to use what we call misshapen or ugly produce. Join our Ugly Produce is Beautiful℠ Educational Campaign, helping to bring awareness to our Nation's enormous food waste problem. This recipe shows you how to use ugly produce in beautiful and delicious ways!VEGETABLE INGREDIENT HELP

INSTRUCTIONS
STEP I: ROAST THE TOMATOES AND PROCESS
1. Position two oven shelves: one one-third from the bottom and the other, one-third from the top of the oven. Line two rimmed baking sheets with foil.
Heat the the oven to 375 degrees F.

2. Place tomatoes of similar size per baking sheet, cut-side up.
Add the sweet potato slices. Add the garlic cloves.

3. Drizzle all over with olive oil.

4. Bake for 30 - 60 minutes, or until softened depending on size.

5. Remove from the oven and let tomatoes, potato slices, and garlic cool in their baking sheets.

6. When cool enough to handle, turn each tomato over, peel off the skin, and cut off any tough cores.
Let any juices and as many seeds as you can fall back onto the baking sheet.
SARAH SAYS: I didn't skin or seed the small heirloom tomatoes, but heirloom tomato skins are thin, and will puree nicely.

7. Place the remaining tomato pulp into a food processor fitted with a steel blade.

8. Remove the skins from the roasted potato slices and add the potatoes to the food processor. Add the roasted garlic and basil leaves.
Discard the tomato and potato skins. Save the excess tomato juice to thin the sauce after cooking, if desired.

9. Process the contents on the food processor until well-blended. The sauce, at this point, will be lumpy and have seeds.

STEP II: COOK THE TOMATOES
1. In a large cooking pot, place the tomato puree and cook on medium-low to low heat until bubbling and sauce thickens and reduces in volume, stirring often so it does not burn.

2. Process the contents in a blender (not a food processor), until smooth. Add salt and pepper to taste.
If necessary, thin with any saved tomato juices. Reheat under low heat, stirring often.